A pinhole leak has been found on a reactor vessel head cooling system at Oyster Creek Generating Station, according to Nuclear Regulatory Commission (NRC) spokesman Neil Sheehan.
The leak was discovered on Tuesday during a refueling and maintenance outage that began at the nuclear power plant on Oct. 22. The system is utilized to cool the reactor vessel head during shutdown, he said.
The pinhole leak was found through an earlier weld and was weeping approximately two to three drops per minute, he said.
“Exelon will need to develop a repair plan that is consistent with the American Society of Mechanical Engineers Code (ASME),” Sheehan said. “NRC metallurgical specialists will continue to engage Exelon on the leak, including a review of the company’s characterization of the flaw and its repair plan.”
Oyster Creek is in the process of addressing the issue, plant spokeswoman Suzanne D’Ambrosio said.
“As soon as it was identified, we put together a repair plan. Essentially what we’re doing is welding it,” she said.
The leak, which is unrelated to the “indications” found and repaired in the reactor nozzle recently, will be repaired according to standards set by the ASME prior to the plant returning online, she said. The finding is a “standard course” of a refueling outage.
“Hundreds and hundreds of inspections are done to make sure when we go back online, we’re 100 percent safe and ready to operate. We wouldn’t go back online if we did tests and found imperfections,” she said.
Inspections and maintenance tests are ongoing at Oyster Creek and D’Ambrosio could not say when the plant intends to return online.
“None of this compromises the safety and integrity of the plant,” she said. “If something’s not the way we want it to be, we need to look at it, make repairs and make changes so that component is operating exactly the way we want it to… We’re moving towards restarting. Restarting the reactor is a very careful and deliberate process so it takes some time.”
Anti-nuclear activist Janet Tauro found it “ironic” that the leak was discovered the same day the NRC denied a petition that calls on the federal agency and Gov. Chris Christie to ensure that “major flaws” at the power plant are addressed before returning online.
“That was tremendously irresponsible and not a surprise. There’s an incredible amount of stress and fatigue on the components. These are serious safety issues,” said Tauro, chair of the Board of Directors of the NJ Environmental Federation (NJEF) and founder of Grandmothers, Mothers and More for Energy Safety (GRAMMES).
Expert Witness Arnie Gunderson, a consultant from Fairewinds Energy Education, said that the problems recently discovered at Oyster Creek are all age related.
“Because of its age, it’s in jeopardy. The crack and this pipe are age-drelated. The fact that it doesn’t have a High Pressure Injection System is age-related,” he said.
Oyster Creek is the only nuclear plant in the country that does not have a High Pressure Coolant Injection System that is designed to cool the plant in the event of a small line break, he said. The safety system was required in all plants after Oyster Creek and because the Forked River plant doesn’t have one, workers must manually reduce pressure in the reactor.
“The crack found in the nozzle, that would have been a small line break,” said Gundersen, who studied nuclear engineering and was a licensed reactor operator.
The pinhole leak is a larger issue than the NRC and Exelon is letting on, he said.
“Pinhole leaks rapidly grow when in use. The pinhole wouldn’t have been a pinhole very long,” he said.
The leak should not just be repaired but plant operators should examine the entire piping with an ultrasound to find out if there’s further damage, he said.
“How many other pinhole leaks are there and what’s the cause,” he said. “I’m afraid the NRC and Oyster Creek are just sweeping this under the rug to start back up.”
Tauro also questions if the plant has other “indicators” or leaks and if Exelon has done the proper modeling to predict these safety problems and prevent them from recurring before the next refueling and maintenance outage, she said.
“How do we know with absolute confidence that this reactor is safe to operate for four more years? They need to prove it. Release to the public for independent review. And if they can’t or won’t, then Oyster Creek should remain shut,” she said.
GRAMMES, NJEF and Beyond Nuclear will be sending the petition to a Petition Review Board for further review, Tauro said.
“Too many things went wrong here in the last six weeks. The NRC has to rethink allowing Oyster Creek to return to operation before making improvements. I’m not saying to shut it down. I’m saying for improvements to be made,” said Gundersen, who is unassociated with the petition.